By experimentation, it replaces all occurrences of the character sequence to the left of the = with the character sequence to the right of the = In this case all zeros are replaced with nothing. In the following the first "02" is replaced with "__"

@jagabo. Thank you much. I needed to replace zeros but couldn't for the life of me figure out how it worked or find reference to it except in the example i found. Thanks again.

Update. Once you let me know it 'replaces characters i went searching again and found a reference in case anyone reads and needs this in the future. Thanks again jagabo. Master of video as well as programming! Lolhttps://ss64.com/nt/syntax-replace.html